A reverse CNAME search is possible

DNS records: how do DNS records work?

value

Type

description

1

A.

Address specifies the IPv4 address of a host.

2

NS

Name server clears the authority of a zone.

3

MD

Mail destination was replaced by the MX record (obsolete).

4

MF

Mail forwarder was replaced by the MX record (obsolete).

5

CNAME

Canonical name defines an alias.

6

SOA

Start of Authority announces details about the zone.

7

MB

Mailbox domain name is experimental.

8

MG

Mail Group Member is experimental.

9

MR

Mail Rename Domain Name is experimental.

10

ZERO

Zero resource is experimental.

11

WKS

Well known service was used for mail forwarding (now obsolete).

12

PTR

pointer is intended for reverse lookup.

13

HINFO

Host information provides hardware and software details of the host.

14

MINFO

Mailbox information is experimental.

15

MX

Mail Exchange assigns a domain to e-mail servers.

16

TXT

text offers the option of entering additional text.

17

RP

Responsible person provides information on those responsible.

18

AFSDB

AFS database is specially intended for AFS clients.

19

X25

X.25 PSDN Address provides details on encapsulation via X.25 (obsolete).

20

ISDN

The entry assigns the DNS name a ISDNNumber to (obsolete).

21

RT

Route Through Record offers route-through binding without a WAN address (obsolete).

22

NSAP

Entry allows assignment of domain names to Network Service Access Points (obsolete).

23

NSAP-PTR

NSAP pointer was replaced by PTR (obsolete).

24

SIG

Signature was replaced by RRSIG (obsolete).

25

KEY

Key was replaced by IPSECKEY (obsolete).

26

PX

Pointer to X.400 specifies MIXER mapping rules (obsolete).

27

GPOS

Geographical position was replaced by LOC (obsolete).

28

AAAA

AAAA provides the IPv6 address of a host.

29

LOC

Location contains information about the location.

30

NXT

Next was replaced by NSEC (obsolete).

31

OATH

Endpoint Identifier is intended for Nimrod Routing Architecture (obsolete).

32

NIMLOC

Nimrod locator is intended for Nimrod Routing Architecture (obsolete).

33

SRV

Service locator informs about further services.

34

ATMA

ATM Address provides information in the context of the asynchronous transfer mode (obsolete).

35

NAPTR

Naming Authority Pointer is an extension of the A record that allows search patterns (regular expressions).

36

KX

Key exchanger enables key management for cryptography.

37

CERT

Cert stores certificates.

38

A6

A6 was replaced by AAAA.

39

DNAME

Delegation name specifies aliases for entire domains.

40

SINK

Kitchen sink allows different data to be saved (obsolete).

41

OPT

option is a pseudo-record in the context of DNS extension mechanisms (EDNS).

42

APL

Address Prefix List lists address ranges in CIDR format.

43

DS

Delegation Signer identifies DNSSEC-signed zones.

44

SSHFP

SSH public key fingerprint publishes the fingerprint for SSH keys.

45

IPSECKEY

IPsec key contains a key for IPsec.

46

RRSIG

RR Signature contains a digital signature for ((DNSSEC | server / knowhow / dnssec-signed-name-resolution /)).

47

NSEC

Next Secure concatenates signed zones in DNSSEC.

48

DNSKEY

DNS key contains a public key for DNSSEC.

49

DHCID

DHCP identifier links domain names with DHCP clients.

50

NSEC3

Next Secure 3 is an alternative to NSEC.

51

NSEC3PARAM

This entry contains parameter for NSEC3.

52

TLSA

This entry creates a TLSA Certificate Association with a domain name under DANE.

53

SMIMEA

This entry creates a S / MIME Certificate Association with a domain name.

54

n / A

Unallocated

55

HIP

Host Identity Protocol separates endpoint tagging and location functions from IP addresses.

56

NINFO

NINFO provides information on the status of the zone (identical structure to TXT; obsolete).

57

RKEY

RKEY saves keys (identical structure to KEY and DNSKEY; obsolete).

58

TALINK

Trust anchor link connects two domain names (obsolete).

59

CDS

Child DS is a child copy of a DS record.

60

CDNSKEY

Child DNSKEY is a child copy of a DNSKEY record.

61

OPENPGPKEY

OpenPGP key publishes public keys.

62

CSYNC

Child-to-Parent Synchronization enables the comparison of parent and child zones (obsolete).

63

ZONEMD

Message Digest for DNS Zone is experimental (obsolete).

64–98

n / A

Unallocated.

99

SPF

Sender Policy Framework was replaced by the TXT record (obsolete).

100

UINFO

Reserved.

101

UID

Reserved.

102

GID

Reserved.

103

UNSPEC

Reserved.

104

NID

NodeID is experimental.

105

L32

32-bit locator is experimental.

106

L64

64-bit locator is experimental.

107

LP

Locator pointer is experimental.

108

EUI48

48-bit Extended Unique Identifier encrypts addresses.

109

EUI64

64-bit Extended Unique Identifier encrypts addresses.

110–248

n / A

Unallocated.

249

TKEY

Transaction Key enables the exchange of secret keys.

250

TSIG

Transaction Signature is used for authentication.

251

IXFR

Incremental Zone Transfer allows parts of a zone file to be updated on a second server (obsolete).

252

AXFR

AFXR transfers a complete zone file to a second server (obsolete).

253

MAILB

Mailbox asks for entries around a mailbox (obsolete).

254

MAILA

Mail agent was replaced by the MX record (obsolete).

255

*

* asks for all entries (obsolete).

256

URI

Uniform Resource Identifier publishes the mapping of host names to URIs.

257

CAA

Certificate Authority Authorization specifies the possible CAs for a domain.

258

AVC

Application Visibility and Control contains application metadata for DNS-AS (obsolete).

259

DOA

DOA is no longer active (obsolete).

260

AMTRELAY

Automatic multicast tunneling relay enables AMT relays to be found (obsolete).

261–32767

n / A

Not forgiven.

32768

TA

DNSSEC Trust Authorities enables DNSSEC without signed root.

32769

DLV

DNSSEC Lookaside Validation publishes Trust Anchors outside the normal DNS chain.

32770–65279

n / A

Unallocated.

65280–65534

n / A

For private use.

65535

n / A

Reserved.